There is no precise moment when a word stops being "new", but 15–20 years is a common cutoff (corresponding to one generation growing up potentially familiar with the word, depending on how common it is). Acceptance of a word as valid by dictionaries or by a significant portion of the population are sometimes mentioned as additional conditions. Some neologisms become widespread and standard (such as new chemical element names), others remain rare or slangy. (Distinguish from protologisms, coinages which have not become common.)